Scanf.scanf "%d" (fun n ->
    let level = Array.make 7 0 in
    for i = 1 to n do
        Scanf.scanf " %d" (fun l -> level.(l) <- level.(l) + 1)
    done;

    let rec loop i mxl mxu =
        if i = 0 then mxl else
            if level.(i) > mxu then loop (i - 1) i level.(i)
                               else loop (i - 1) mxl mxu
    in
    loop 6 0 0 |> Printf.printf "%d\n"
)